Fix/OpenAI embedding dimensions 4153 (#4481)

mem0/embeddings/openai.py

@@ -13,6 +13,9 @@ class OpenAIEmbedding(EmbeddingBase):
         super().__init__(config)
 
         self.config.model = self.config.model or "text-embedding-3-small"
+        # Only pass `dimensions` to the API when the user set embedding_dims; non-matryoshka
+        # OpenAI-compatible backends (vLLM, Voyage, etc.) reject the parameter
+        self._pass_dimensions_to_api = self.config.embedding_dims is not None
         self.config.embedding_dims = self.config.embedding_dims or 1536
 
         api_key = self.config.api_key or os.getenv("OPENAI_API_KEY")
@@ -42,13 +45,11 @@ class OpenAIEmbedding(EmbeddingBase):
             list: The embedding vector.
         """
         text = text.replace("\n", " ")
-        return (
-            self.client.embeddings.create(
-                input=[text],
-                model=self.config.model,
-                dimensions=self.config.embedding_dims,
-                encoding_format="float",
-            )
-            .data[0]
-            .embedding
-        )
+        kwargs = {
+            "input": [text],
+            "model": self.config.model,
+            "encoding_format": "float",
+        }
+        if self._pass_dimensions_to_api:
+            kwargs["dimensions"] = self.config.embedding_dims
+        return self.client.embeddings.create(**kwargs).data[0].embedding